1. Field of the Invention
The present invention relates to a socket connector, and more particularly to a socket connector featured with a plurality of contact terminal units each comprises an insulated elastomer with a contact terminal supported thereon.
2. Description of the Related Art
With the development of technology, electrical socket connectors, which typically categorized into LGA and PGA in view of their mating interface with the electronic devices, have widely implemented in computers and other electrical devices for transmitting signals and conductive current between a printed circuit board (PCB) and an integrated circuit (IC) package.
A typical LGA socket connector comprises a plastic housing (such as terminal carriers) and multiple metal copper alloy terminals. As the market asks for more pin counts and smaller socket connector in dimension, a design of a new type LGA socket connector becomes more and more challenging due to a space required for terminal arms and an increasing loading force.
U.S. Pat. No. 7,658,616 submitted by IBM on Dec. 4, 2008 discloses a related land grid array (LGA) socket connector. The land grid array (LGA) socket connector comprises an insulating carrier plane and at least one interposer mounted on a first surface of said carrier plane.
The interposer selectively has a hemi-toroidal, conical, dome-shaped conic section, generally cylindrical or hemi-spherical configuration in transverse cross-section and is constituted of a dielectric elastomeric material. A plurality of electrically-conductive elements are arranged about the surface of said at least one hemi-toroidal interposer and extend radially inwardly and downwardly from an uppermost end thereof to electrically contact with an electrically conductive pad.
The insulating carrier plane has at least one via formed therein. The electrically-conductive pad extends through said at least one via and has portions contacting with the upper surface of said insulating carrier plane. The electrically-conductive elements each comprises a plurality of metallic strips contacting with an upper surface of said pad. The interposers of essentially conical or dome-shaped conic sections are arranged in pairs and in groups with a predetermined number of said interposers. In each said group, the electrically-conductive elements of each said interposers joint with proximate said at least one via in said insulating carrier plane and contact with said pad to form a common connection at a lower surface of said insulating carrier plane, and each of the interposers in one group differs in height from another one in another group.
One of the problems is that when the electrically-conductive elements become smaller and smaller, the electrically-conductive element tends to crash or deform beyond its yielding point easily such that a permanent deformation will be encountered. Once the electrically-conductive elements are crashed, it is unlikely to provide sufficient normal force which is absolutely required for a reliable and robust interconnection. Accordingly, once the electrically-conductive element becomes smaller and smaller, an auxiliary support is therefore required.
Hence, an improved socket connector is required to overcome the disadvantages of the prior art.